Messages in this thread Patch in this message | | | Date | Thu, 11 May 2006 14:22:14 +0800 | From | Lin Feng Shen <> | Subject | [PATCH 1/1] NFS: fix error handling on access_ok in compat_sys_nfsservctl |
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From: Lin Feng Shen <shenlinf@cn.ibm.com>
Functions compat_nfs_svc_trans, compat_nfs_clnt_trans, compat_nfs_exp_trans, compat_nfs_getfd_trans and compat_nfs_getfs_trans, which are called by compat_sys_nfsservctl(fs/compat.c), don't handle the return value of access_ok properly. access_ok return 1 when the addr is valid, and 0 when it's not, but these functions have the reversed understanding. When the address is valid, they always return -EFAULT to compat_sys_nfsservctl.
An example is to run /usr/sbin/rpc.nfsd(32bit program on Power5). It doesn't function as expected. strace showes that nfsservctl returns -EFAULT.
The patch fixes this by correcting the error handling on the return value of access_ok in the five functions. It is created against linux-2.6.17-rc3-git16.
Signed-off-by: Lin Feng Shen <shenlinf@cn.ibm.com> ---
--- linux-2.6.17-rc3-git16/fs/compat.c.orig 2006-05-09 09:07:38.000000000 -0500 +++ linux-2.6.17-rc3-git16/fs/compat.c 2006-05-09 09:21:00.000000000 -0500 @@ -2032,101 +2032,96 @@ union compat_nfsctl_res { static int compat_nfs_svc_trans(struct nfsctl_arg *karg, struct compat_nfsctl_arg __user *arg) { - int err; - - err = access_ok(VERIFY_READ, &arg->ca32_svc, sizeof(arg->ca32_svc)); - err |= get_user(karg->ca_version, &arg->ca32_version); - err |= __get_user(karg->ca_svc.svc_port, &arg->ca32_svc.svc32_port); - err |= __get_user(karg->ca_svc.svc_nthreads, &arg->ca32_svc.svc32_nthreads); - return (err) ? -EFAULT : 0; + if(!access_ok(VERIFY_READ, &arg->ca32_svc, sizeof(arg->ca32_svc)) || + get_user(karg->ca_version, &arg->ca32_version) || + __get_user(karg->ca_svc.svc_port, &arg->ca32_svc.svc32_port) || + __get_user(karg->ca_svc.svc_nthreads, &arg->ca32_svc.svc32_nthreads)) + return -EFAULT; + return 0; } static int compat_nfs_clnt_trans(struct nfsctl_arg *karg, struct compat_nfsctl_arg __user *arg) { - int err; - - err = access_ok(VERIFY_READ, &arg->ca32_client, sizeof(arg->ca32_client)); - err |= get_user(karg->ca_version, &arg->ca32_version); - err |= __copy_from_user(&karg->ca_client.cl_ident[0], + if(!access_ok(VERIFY_READ, &arg->ca32_client, sizeof(arg->ca32_client)) || + get_user(karg->ca_version, &arg->ca32_version) || + __copy_from_user(&karg->ca_client.cl_ident[0], &arg->ca32_client.cl32_ident[0], - NFSCLNT_IDMAX); - err |= __get_user(karg->ca_client.cl_naddr, &arg->ca32_client.cl32_naddr); - err |= __copy_from_user(&karg->ca_client.cl_addrlist[0], + NFSCLNT_IDMAX) || + __get_user(karg->ca_client.cl_naddr, &arg->ca32_client.cl32_naddr) || + __copy_from_user(&karg->ca_client.cl_addrlist[0], &arg->ca32_client.cl32_addrlist[0], - (sizeof(struct in_addr) * NFSCLNT_ADDRMAX)); - err |= __get_user(karg->ca_client.cl_fhkeytype, - &arg->ca32_client.cl32_fhkeytype); - err |= __get_user(karg->ca_client.cl_fhkeylen, - &arg->ca32_client.cl32_fhkeylen); - err |= __copy_from_user(&karg->ca_client.cl_fhkey[0], + (sizeof(struct in_addr) * NFSCLNT_ADDRMAX)) || + __get_user(karg->ca_client.cl_fhkeytype, + &arg->ca32_client.cl32_fhkeytype) || + __get_user(karg->ca_client.cl_fhkeylen, + &arg->ca32_client.cl32_fhkeylen) || + __copy_from_user(&karg->ca_client.cl_fhkey[0], &arg->ca32_client.cl32_fhkey[0], - NFSCLNT_KEYMAX); + NFSCLNT_KEYMAX)) + return -EFAULT; - return (err) ? -EFAULT : 0; + return 0; } static int compat_nfs_exp_trans(struct nfsctl_arg *karg, struct compat_nfsctl_arg __user *arg) { - int err; - - err = access_ok(VERIFY_READ, &arg->ca32_export, sizeof(arg->ca32_export)); - err |= get_user(karg->ca_version, &arg->ca32_version); - err |= __copy_from_user(&karg->ca_export.ex_client[0], + if(!access_ok(VERIFY_READ, &arg->ca32_export, sizeof(arg->ca32_export)) || + get_user(karg->ca_version, &arg->ca32_version) || + __copy_from_user(&karg->ca_export.ex_client[0], &arg->ca32_export.ex32_client[0], - NFSCLNT_IDMAX); - err |= __copy_from_user(&karg->ca_export.ex_path[0], + NFSCLNT_IDMAX) || + __copy_from_user(&karg->ca_export.ex_path[0], &arg->ca32_export.ex32_path[0], - NFS_MAXPATHLEN); - err |= __get_user(karg->ca_export.ex_dev, - &arg->ca32_export.ex32_dev); - err |= __get_user(karg->ca_export.ex_ino, - &arg->ca32_export.ex32_ino); - err |= __get_user(karg->ca_export.ex_flags, - &arg->ca32_export.ex32_flags); - err |= __get_user(karg->ca_export.ex_anon_uid, - &arg->ca32_export.ex32_anon_uid); - err |= __get_user(karg->ca_export.ex_anon_gid, - &arg->ca32_export.ex32_anon_gid); + NFS_MAXPATHLEN) || + __get_user(karg->ca_export.ex_dev, + &arg->ca32_export.ex32_dev) || + __get_user(karg->ca_export.ex_ino, + &arg->ca32_export.ex32_ino) || + __get_user(karg->ca_export.ex_flags, + &arg->ca32_export.ex32_flags) || + __get_user(karg->ca_export.ex_anon_uid, + &arg->ca32_export.ex32_anon_uid) || + __get_user(karg->ca_export.ex_anon_gid, + &arg->ca32_export.ex32_anon_gid)) + return -EFAULT; SET_UID(karg->ca_export.ex_anon_uid, karg->ca_export.ex_anon_uid); SET_GID(karg->ca_export.ex_anon_gid, karg->ca_export.ex_anon_gid); - return (err) ? -EFAULT : 0; + return 0; } static int compat_nfs_getfd_trans(struct nfsctl_arg *karg, struct compat_nfsctl_arg __user *arg) { - int err; - - err = access_ok(VERIFY_READ, &arg->ca32_getfd, sizeof(arg->ca32_getfd)); - err |= get_user(karg->ca_version, &arg->ca32_version); - err |= __copy_from_user(&karg->ca_getfd.gd_addr, + if(!access_ok(VERIFY_READ, &arg->ca32_getfd, sizeof(arg->ca32_getfd)) || + get_user(karg->ca_version, &arg->ca32_version) || + __copy_from_user(&karg->ca_getfd.gd_addr, &arg->ca32_getfd.gd32_addr, - (sizeof(struct sockaddr))); - err |= __copy_from_user(&karg->ca_getfd.gd_path, + (sizeof(struct sockaddr))) || + __copy_from_user(&karg->ca_getfd.gd_path, &arg->ca32_getfd.gd32_path, - (NFS_MAXPATHLEN+1)); - err |= __get_user(karg->ca_getfd.gd_version, - &arg->ca32_getfd.gd32_version); + (NFS_MAXPATHLEN+1)) || + __get_user(karg->ca_getfd.gd_version, + &arg->ca32_getfd.gd32_version)) + return -EFAULT; - return (err) ? -EFAULT : 0; + return 0; } static int compat_nfs_getfs_trans(struct nfsctl_arg *karg, struct compat_nfsctl_arg __user *arg) { - int err; - - err = access_ok(VERIFY_READ, &arg->ca32_getfs, sizeof(arg->ca32_getfs)); - err |= get_user(karg->ca_version, &arg->ca32_version); - err |= __copy_from_user(&karg->ca_getfs.gd_addr, + if(!access_ok(VERIFY_READ, &arg->ca32_getfs, sizeof(arg->ca32_getfs)) || + get_user(karg->ca_version, &arg->ca32_version) || + __copy_from_user(&karg->ca_getfs.gd_addr, &arg->ca32_getfs.gd32_addr, - (sizeof(struct sockaddr))); - err |= __copy_from_user(&karg->ca_getfs.gd_path, + (sizeof(struct sockaddr))) || + __copy_from_user(&karg->ca_getfs.gd_path, &arg->ca32_getfs.gd32_path, - (NFS_MAXPATHLEN+1)); - err |= __get_user(karg->ca_getfs.gd_maxlen, - &arg->ca32_getfs.gd32_maxlen); + (NFS_MAXPATHLEN+1)) || + __get_user(karg->ca_getfs.gd_maxlen, + &arg->ca32_getfs.gd32_maxlen)) + return -EFAULT; - return (err) ? -EFAULT : 0; + return 0; } /* This really doesn't need translations, we are only passing - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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